Change the get_user_pages() call with fast_gup() which doesn't require holding the mmap_sem thereby removing the mmap_sem from all fast paths. Signed-off-by: Peter Zijlstra --- kernel/futex.c | 4 +--- 1 file changed, 1 insertion(+), 3 deletions(-) Index: linux-2.6/kernel/futex.c =================================================================== --- linux-2.6.orig/kernel/futex.c +++ linux-2.6/kernel/futex.c @@ -232,9 +232,7 @@ static int get_futex_key(u32 __user *uad } again: - down_read(&mm->mmap_sem); - err = get_user_pages(current, mm, address, 1, 0, 0, &page, NULL); - up_read(&mm->mmap_sem); + err = get_user_pages_fast(address, 1, 0, &page); if (err < 0) return err; -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org